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PopSci's 6th Annual Brilliant Ten
We visit operating rooms, observatories, and islands full of slightly-less-than-rational monkeys to find the young geniuses who are shaping the future of science

Collision Detective
Frans Pretorius, 34; Princeton University
His computer simulations predict what happens when black holes collide
A black hole is a bit like the Invisible Man: You cann't see it directly, but you might be able to catch a glimpse of its footprints. With black holes, however, you must first figure out what these footprints look like. Thanks to Frans Pretorius, we now have a pretty good idea. black holes consume everything, including light, scientists can find them only by searching for their gravitational energy. A collision between two black holes is one of the most powerful events in the universe, a cataclysm equivalent to 500 million supernovae convulsing the fabric of spacetime. Scientists now watch for signs of the resultant ripples—the first gravitational-wave detectors sensitive enough to spot these collisions are already operational, and a handful of others will begin gathering data over the next few decades. To distinguish these waves from background noise, physicists must simulate how the waves will appear when they reach Earth. They do this by solving Einstein's equations of general relativity at millions of points over a 3-D grid of space—the only way the computers can churn through the calculations  like a game of Telephone, these translations can introduce minor errors that rapidly accumulate, turning the information into gibberish. Despite 40 years of effort, these errors always crashed the computers of the groups struggling to run the simulations. Some feared the problem was unsolvable. Then Pretorius, at the time a postdoc at the California Institute of Technology, single-handedly solved the problem in a year. His trick was to make the translation—and therefore the simulation—as simple as possible. "I said, 'Well, I might as well give this a shot,' " he recalls, shrugging. "It turned out to work."

His colleagues saw it differently. "[It was as if he] went into his garage, built a fully operational Saturn 5 rocket, and flew it to the moon all on his own," says Neil Cornish, a physicist at Montana State University. Other groups achieved success just months later. "By showing that it could be done," Cornish says, "he inspired others to find a way out of the maze." Pretorius is not done with Einstein. He is using his models to see what the proton collisions at the Large Hadron Collider—the particle accelerator in Geneva scheduled to switch on next spring—would look like, if those proton collisions created miniature black holes. If they do, it would be the first evidence that we live in a multiverse, a universe with hidden dimensions. Those three dimensions we have always known? They would be revealed as mere footprints, traces from an invisible world.—M.W.
  

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